This application is based on Patent Application No. 2000-126598 filed Apr. 26, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to an ink tank, an ink jet recording head, an ink jet cartridge, and an ink jet recording apparatus.
The present invention is applicable to general print apparatuses as recording apparatuses, copiers, facsimile terminal equipment having a communication system, apparatuses such as word processors which have a print section, and industrial print apparatuses combined with various processing apparatuses.
2. Description of the Related Art
Known serial-scan-based ink jet recording apparatuses comprise a carriage that is movable in a main scan direction, an ink jet recording head acting as recording means, and an ink tank acting as an ink container, both the ink jet recording head and the ink tank being replaceably mounted on the carriage. The recording head and the ink tank are connected together via an ink passage. In such a recording apparatus, an image can sequentially be recorded on a recorded medium such as recording paper by repeating a main scan of the carriage with the recording head and the ink tank mounted thereon and a subscan of the recorded medium.
On the other hand, a possible method of supplying an ink to the ink tank of the ink jet recording apparatus is, for example, to suck and supply the ink by pressurizing the ink to introduce negative pressure into the ink.
One configuration that can be used if the ink is sucked and supplied as described above will be described below as a method for supplying an ink to an ink tank a the recording head connected thereto.
As shown in FIG. 9, in, for example, a serial-scan-based ink jet recording apparatus, a storage ink tank 20 acting as a sub-ink tank has an ink jet recording head 20a (hereafter simply referred to as a xe2x80x9crecording headxe2x80x9d) capable of ejecting an ink for recording and is removably mounted on a carriage (not shown). The recording head 20a ejects the ink from the storage ink tank 20 through an ink ejecting port in a nozzle 44 based on image information. Further, the storage ink tank 20 has an ink supplying port 20f for supplying the ink from the storage ink tank 20 to the recording head 20a. The nozzle 44 in the recording head 20a includes an ejection energy generating means for generating energy required to eject the ink. The ejection energy generating means may comprise an electrothermal converter for generating thermal energy. The carriage is moved by an appropriate movement mechanism in the main scan direction shown by arrows 28 and 35. Further, recorded media are conveyed in a subscan direction crossing the main scan direction.
In such a recording apparatus, an image can sequentially be recorded on the recorded medium by repeating a main scan of the carriage with the recording head 20a and the storage ink tank 20 mounted thereon and a subscan of the recorded medium.
The storage ink tank 20 has a suction port 53 and an ink intake port 20b formed in a side thereof. The suction port 53 is in communication with the interior of the storage ink tank 20 via a suction passage 53a, and a gas transmitting member 48 is provided at the site of the opening of the suction passage 53a in the storage ink tank 20. The gas transmitting member 48 has, as a gas-liquid separating means, a function of transmitting gases therethrough while not transmitting inks therethrough. For example, the gas transmitting member 48 preferably comprise a thin sheet formed of an ethylene tetrafluorice resin, a similar porous resin material, or the like. Additionally, the storage ink tank 20 has an ink absorber 41a accommodated therein, for sucking and holding the ink.
The storage ink tank 20 includes a filter 103 and a valve 104 in the supplying port 20f. The valve 104 is shaped like a seat and has its proximal end welded to the filter 103. The valve 104 functions to open and close the supplying port 20f depending on the internal pressure of the storage ink tank 20.
Further, a main tank 22 of the recording apparatus main body is disposed via a tube 21a with a supplying joint 101, so as to be connectable to the ink intake port 20b in the storage ink tank 20. The joint 101 and a joint 102 are disposed in the recording apparatus main body so as to lie opposite to the ink intake port 20b and the suction port 53 in the scan direction 35 of the carriage.
During a recording operation, the valve 104 is open and the ink is supplied from the storage ink tank 20 to the recording head 20a, as shown in FIG. 9.
FIGS. 10 to 14 are views useful in explaining an operation of refilling the above described ink tank with the ink.
In ink refilling, the carriage is first moved in the direction of the arrow 28 to connect the ink intake port 20b and the suction port 53 to the corresponding joints 101 and 102, as shown in FIG. 10. Subsequently, the suction pump 31 performs a suction operation to suck air from the storage ink tank 20 via the gas transmitting member 48 to set the interior of the storage ink tank 20 at negative pressure. The negative pressure in the storage ink tank 20 causes the ink in the main tank 22 to be sucked to the interior of the storage ink tank 20 as shown in FIGS. 11 and 12.
In this case, the negative pressure in the storage ink tank 20 causes the valve 104 to operate in such a way as to close the supplying port 20f, as shown in FIGS. 11 and 12. Accordingly, the ink in the recording head 20a is not sucked to the interior of the storage ink tank 20, and ink meniscus formed at the ink ejecting port in the recording head 20a is not destroyed. Further, air does not enter the recording head 20a or the storage ink tank 20 through the ink ejecting port. This ensures that the ink is sucked from the main tank 22 and supplied to the interior of the storage ink tank 20.
Then, as shown in FIG. 13, when the level 41b of the ink in the storage ink tank 20 reaches the gas transmitting member 48, the ink refilling is automatically stopped because the gas transmitting member 48 does not transmit liquids such as inks therethrough. Subsequently, as shown in FIG. 14, the carriage moves in the direction of the arrow 35 to separate the ink intake port 20b and the suction port 53 from the corresponding joints 101 and 102, thereby completing the series of refilling operations.
The above-described conventional ink tank, however, has the following problems:
That is, as described above, when the level 41b of the ink in the storage ink tank 20 reaches the gas transmitting member 48, the ink refilling is automatically stopped because the gas transmitting member 48 does not transmit liquids such as inks therethrough. For a certain gas transmitting member 48, exerting a certain amount or more of negative pressure may destroy the gas transmitting member 48 to eliminate its inherent function of separating a gas and a liquid from each other, thus causing the ink, a liquid, to be also sucked. Consequently, a large amount of ink may be sucked from the storage ink tank 20 to waste the ink, the ink may flow into the suction pump 31 to destroy it, or a waste ink may contaminate the recording apparatus.
It is thus an object of the present invention to provide an ink tank, an ink jet recording head, an ink jet cartridge, and an ink jet recording apparatus which are durable enough to allow the ink tank to be refilled many times and which prevent the original gas-liquid separating function of a gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting means as described above, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
To attain the above object, the present invention provides an ink tank which supplies an ink to an ink jet recording head via an ink supplying port, which can supply the ink by introducing negative pressure thereinside, and which has a gas-liquid separating means in a suction port through which the negative pressure required to suck and supply the ink is introduced, the gas-liquid separating means transmitting gases therethrough while not transmitting the gas therethrough, the ink tank being characterized by having a fixed-negative-pressure generating means provided between the gas-liquid separating means and a source of the negative-pressure required to suck and supply the ink, the fixed-negative-pressure generating means preventing a fixed amount or more of negative pressure from being exerted on the gas-liquid separating means. This provides an ink tank which is durable enough to be refilled with the ink many times and which prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink tank of the present invention is also characterized by including as the fixed-negative-pressure generating means, a suction pump having a negative-pressure sensor. This prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink tank of the present invention is further characterized by including a tube pump as the fixed-negative-pressure generating means. This prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink tank of the present invention is further characterized by including a diaphragm pump as the fixed-negative-pressure generating means. This prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The present invention provides an ink jet recording head installed on an ink tank which supplies an ink to an ink jet recording head via an ink supplying port, which can supply the ink by introducing negative pressure thereinside, and which has a gas-liquid separating means in a suction port through which the negative pressure required to suck and supply the ink is introduced, the gas-liquid separating means transmitting gases therethrough while not transmitting the gas therethrough, the ink jet recording head being characterized by having a fixed-negative-pressure generating means provided between the gas-liquid separating means and a source of the negative-pressure required to suck and supply the ink, the fixed-negative-pressure generating means preventing a fixed amount or more of negative pressure from being exerted on the gas-liquid separating means. This prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet recording head of the present invention is also characterized by including as the fixed-negative-pressure generating means, a suction pump having a negative-pressure sensor. This enables the ink jet recording head to be appropriately produced so as to have a simple configuration, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet recording head of the present invention is further characterized by including a tube pump as the fixed-negative-pressure generating means. This enables the ink jet recording head to be appropriately produced so as to have a simple configuration, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet recording head of the present invention is further characterized by having a diaphragm pump as the fixed-negative-pressure generating means. This enables the ink jet recording head to be appropriately produced so as to have a simple configuration.
The present invention provides an ink jet cartridge having an ink tank installed therein, which supplies an ink to an ink jet recording head via an ink supplying port, which can supply the ink by introducing negative pressure thereinside, and which has a gas-liquid separating means in a suction port through which the negative pressure required to suck and supply the ink is introduced, the gas-liquid separating means transmitting gases therethrough while not transmitting the gas therethrough, the ink jet cartridge being characterized by having a fixed-negative-pressure generating means provided between the gas-liquid separating means and a source of the negative-pressure required to suck and supply the ink, the fixed-negative-pressure generating means preventing a fixed amount or more of negative pressure from being exerted on the gas-liquid separating means. This enables the ink jet cartridge to be appropriately produced so as to have a simple configuration, and prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet cartridge of the present invention is also characterized by including as the fixed-negative-pressure generating means, a suction pump having a negative-pressure sensor. This enables the ink jet cartridge to be appropriately produced so as to have a simple configuration, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet cartridge of the present invention is further characterized by including a tube pump as the fixed-negative-pressure generating means. This enables the ink jet cartridge to be appropriately produced so as to have a simple configuration, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet cartridge of the present invention is further characterized by including a diaphragm pump as the fixed-negative-pressure generating means. This enables the ink jet cartridge to be appropriately produced so as to have a simple configuration, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet cartridge of the present invention is further characterized by having a diaphragm pump as the fixed-negative-pressure generating means. This enables the ink jet cartridge to be appropriately produced so as to have a simple configuration.
The present invention provides an ink jet recording apparatus having an ink tank which supplies an ink to an ink jet recording head via an ink supplying port and which can supply the ink by introducing negative pressure thereinside, the ink jet recording apparatus having a gas-liquid separating means in a suction port through which the negative pressure required to suck and supply the ink is introduced, the gas-liquid separating means transmitting gases therethrough while not transmitting the gas therethrough, the ink jet recording apparatus being characterized by having a fixed-negative-pressure generating means provided between the gas-liquid separating means and a source of the negative-pressure required to suck and supply the ink, the fixed-negative-pressure generating means preventing a fixed amount or more of negative pressure from being exerted on the gas-liquid separating means. This provides an ink jet recording apparatus which is durable enough to be refilled with the ink many times and which prevents the original gas-liquid separating function of the gas transmitting member as a gas-liquid separating means from being destroyed due to excessive negative pressure exerted on the gas transmitting member, thereby achieving an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet recording apparatus of the present invention is also characterized by including as the fixed-negative-pressure generating means, a suction pump having a negative-pressure sensor. This serves to achieve an appropriate ink refilling operation and a reliable ink sucking and supplying operation, and enables the ink jet recording apparatus to be appropriately produced so as to have a simple configuration.
The ink jet recording apparatus of the present invention is further characterized by including a tube pump as the fixed-negative-pressure generating means. This serves to achieve an appropriate ink refilling operation and a reliable ink sucking and supplying operation.
The ink jet recording apparatus of the present invention is further characterized by having a diaphragm pump as the fixed-negative-pressure generating means. This allows the ink to flow appropriately to achieve stable ink refilling and supplying operations.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.